This invention relates to child-resistant closures and containers. More specifically, this invention relates to a child-resistant closure and container combination which incorporates an improved vapor-sealing liner system.
A serious problem that has long existed with respect to the handling of drugs is that drugs are often packaged in containers that can be readily opened by children, resulting in many serious injuries or deaths. A variety of child-resistant safety closures have been introduced, such as the safety cap and container discussed in the U.S. Pat. to Hedgewick, No. 3,344,942, issued Oct. 3, 1967. The problem with this safety closure and many others is that its construction provides no means for preventing moisture vapor from penetrating through to the contents of the container. It has been found that exposure to moisture vapor can be very destructive to various types of medicines.
Various attempts have been made to incorporate a vapor seal into a safety closure, such as, for example, those concepts taught by the U.S. Pat. Nos. to Hedgewick et al, 3,478,911 issued Nov. 18, 1969, and Hedgewick et al, 3,485,403 issued Dec. 23, 1969. However, it has been found that the sealing liners suggested by the aforementioned Hedgewick patents have not been sufficiently resilient to withstand repeated opening and reapplication of the closure to the container. Thus, the vapor-sealing effectiveness of such constructions has dimished with continued use of these devices over a period of time.